// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_MIDI_USB_MIDI_INPUT_STREAM_H_
#define MEDIA_MIDI_USB_MIDI_INPUT_STREAM_H_

#include <stddef.h>
#include <stdint.h>

#include <map>
#include <vector>

#include "base/containers/hash_tables.h"
#include "base/macros.h"
#include "base/time/time.h"
#include "media/midi/usb_midi_export.h"
#include "media/midi/usb_midi_jack.h"

namespace midi {

class UsbMidiDevice;

// UsbMidiInputStream converts USB-MIDI data to MIDI data.
// See "USB Device Class Definition for MIDI Devices" Release 1.0,
// Section 4 "USB-MIDI Event Packets" for details.
class USB_MIDI_EXPORT UsbMidiInputStream {
public:
    class USB_MIDI_EXPORT Delegate {
    public:
        virtual ~Delegate() { }
        // This function is called when some data arrives to a USB-MIDI jack.
        // An input USB-MIDI jack corresponds to an input MIDIPortInfo.
        virtual void OnReceivedData(size_t jack_index,
            const uint8_t* data,
            size_t size,
            base::TimeTicks time)
            = 0;
    };

    // This is public for testing.
    struct JackUniqueKey {
        JackUniqueKey(UsbMidiDevice* device, int endpoint_number, int cable_number);
        bool operator==(const JackUniqueKey& that) const;
        bool operator<(const JackUniqueKey& that) const;

        UsbMidiDevice* device;
        int endpoint_number;
        int cable_number;
    };

    explicit UsbMidiInputStream(Delegate* delegate);
    ~UsbMidiInputStream();

    void Add(const UsbMidiJack& jack);

    // This function should be called when some data arrives to a USB-MIDI
    // endpoint. This function converts the data to MIDI data and call
    // |delegate->OnReceivedData| with it.
    // |size| must be a multiple of |kPacketSize|.
    void OnReceivedData(UsbMidiDevice* device,
        int endpoint_number,
        const uint8_t* data,
        size_t size,
        base::TimeTicks time);

    const std::vector<UsbMidiJack>& jacks() const { return jacks_; }

private:
    static const size_t kPacketSize = 4;
    // Processes a USB-MIDI Event Packet.
    // The first |kPacketSize| bytes of |packet| must be accessible.
    void ProcessOnePacket(UsbMidiDevice* device,
        int endpoint_number,
        const uint8_t* packet,
        base::TimeTicks time);

    std::vector<UsbMidiJack> jacks_;
    // A map from UsbMidiJack to its index in |jacks_|.
    std::map<JackUniqueKey, size_t> jack_dictionary_;

    // Not owned
    Delegate* delegate_;

    DISALLOW_COPY_AND_ASSIGN(UsbMidiInputStream);
};

} // namespace midi

#endif // MEDIA_MIDI_USB_MIDI_INPUT_STREAM_H_
